1. Field of the Invention
This invention relates to a semiconductor light-emitting element and a method of manufacturing the semiconductor light-emitting element. In particular, this invention relates to a semiconductor light-emitting element improved in light extraction efficiency, and to a method of manufacturing such a semiconductor light-emitting element.
2. Description of the Related Art
In recent years, a semiconductor light-emitting element, in particular, a light-emitting diode (LED) has been widely utilized as a backlight for a display, as a light source for vehicles, as an illumination source, etc. In these applications, the semiconductor light-emitting element has been demanded to be excellent in emission efficiency. As for one of potent means for enhancing the emission efficiency of the semiconductor light-emitting element, it is conceivable to take measures to enhance the efficiency to extract the light from the light-emitting element and hence there have been reported a large number of studies on this scheme.
For example, there has been proposed to work a substrate so as to have a V-shaped or step-like configuration on the surface thereof, thereby enabling the light being directed toward the bottom of chip to divert so as to enable the light to take up from the side face of these configurations, thus making it possible to enhance the light extraction efficiency (see, for example, JP-A 2004-56088).
There has been also proposed to make a semiconductor substrate into a flip chip so as to substantially annihilate the absorption of light by electrodes (see, for example, JP-A 2004-319685).
However, according to the configurations of the conventional semiconductor light-emitting elements disclosed in these patent publications described above, since the n-electrode and the p-electrode are both disposed on the same plane of chip and the top surface of the n-electrode is not permitted to emit the light, the conventional semiconductor light-emitting elements are accompanied with various problems that the substantial light-emitting area is caused to become smaller, that the electric current density at part of current conducting region is caused to become higher, and that the excitation efficiency is caused to deteriorate, thus giving rise to the deterioration of light-emitting efficiency. Further, the configurations disclosed in the aforementioned patent publications are also accompanied with the problem that the light is absorbed by the electrodes of the top surface of substrate, thus badly affecting the light-emitting efficiency thereof.